WIP on fcb io

kernel/drive.asm

@@ -46,8 +46,18 @@ drive_read:
   dec dl
   mov ax, 0x0201
   mov bx, diskbuf
+  ; try read
   int 0x13
-.giveup:
+  jnc .end
+  ; reset disk
+  mov ah, 0x00
+  int 0x13
+  ; loop with si
+  dec si
+  test si, si
+  jnz .try
+  stc
+.end:
   pop si
   pop bx
   pop dx
@@ -57,27 +67,3 @@ drive_read:
 .fast: ; fast lane for boot sector
   inc cl
   jmp .try
-.fail:
-  ; reset disk
-  mov ah, 0x00
-  int 0x13
-  ; loop with si
-  dec si
-  test si, si
-  jnz .try
-  stc
-  jmp .giveup
-
-; Seek to fcb_off given in a ptr
-; IN	BX	ptr to FCB
-drive_seek:
-  push ax
-  push cx
-  mov cl, [bx+fcb_ss]
-  add cl, 7
-  mov ax, 1
-  sal ax, cl
-  int3
-  pop cx
-  pop ax
-  ret